diff --git a/build.mk b/build.mk
index 65a4db8..567be11 100644
--- a/build.mk
+++ b/build.mk
@@ -3,6 +3,11 @@
 endif
 
 
+ifndef OBJDIR
+OBJDIR = $(BINDIR)/obj
+endif
+
+
 #definition of various tools
 AWK = awk
 CAT = cat
@@ -32,8 +37,6 @@
 endif
 
 
-OBJDIR = $(BINDIR)/obj
-
 #update CFLAGS and LDFLAGS
 CFLAGS += $(PLATFORM_CFLAGS) $(ARCH_CFLAGS) $(OPT_CFLAGS) -O$(OPTLEVEL) -g$(DBGLEVEL) $(addprefix -I, $(INCDIRS)) $(addprefix -D, $(CPPDEFS))
 CXXFLAGS += $(PLATFORM_CXXFLAGS) $(ARCH_CFLAGS) $(OPT_CFLAGS) -O$(OPTLEVEL) -g$(DBGLEVEL) $(addprefix -I, $(INCDIRS)) $(addprefix -D, $(CPPDEFS))
@@ -152,7 +155,7 @@
 
 clean: user_clean_target
 	@echo Cleaning application files ...
-	-$(RM) -rf $(BINDIR)
+	-$(RM) -rf $(BINDIR) $(OBJDIR)
 
 
 $(eval $(call CONFIG_TARGETS))